When trying to play a DVD or a divx movie at fullscreen, the image movement were not fluent, just like a 25fps movie played at 11fps. Similiarly, the 3D screen-savers were slow. Checking the /var/log/Xorg.0.log file everything seemed ok, since the default NV drivers included in Xorg are capable of recognizing the NVidia graphic card. Unfortunately, those driver are definitely not optimized and they perform very bad. NVidia released some alternative drivers for linux and -still- unfortunately, they are propertary. It’s your choice to use the free unoptimized drivers or the propertary optimized ones. Anyway, here follows the procedure to install the propertary ones.

Drivers depends on the architecture used by your system. Nvidia releases driver only for x86 and AMD64 CPUs. To check what’s your architecture, type

uname -r

If your kernel version ends with -*86, follow the blue steps, otherwise if it ends with -amd64 follow the red steps. (NOTE: if you have this video card and are using a x86 kernel, you are probably not using all your PC potential. Consider installing an AMD64 distribution. More information here.)